SDL 2 based rumble tester I use for PS3 controllers

rumble.cpp

#include <SDL2/SDL.h>
#include <cstdio>
#include <list>
#include <signal.h>

std::list<std::pair<SDL_Joystick*, SDL_Haptic*>> joysticks;

void shutdown_joysticks() {
    SDL_Log("Closing joysticks");
    for (std::pair<SDL_Joystick*, SDL_Haptic*> joystick : joysticks) {
        SDL_HapticClose(joystick.second);
        SDL_JoystickClose(joystick.first);
    }

    SDL_Quit();
}

void ctrlc_handler(int s) {
    shutdown_joysticks();
    exit(1);
}

int init_joysticks() {
    int count = SDL_NumJoysticks();
    if (count == 0) {
        SDL_Log("Failed to find any joystick");
        return 1;
    }

    SDL_Log("Found %d joysticks", count);
    for (int i = 0; i < count; i++) {
        SDL_Joystick* joystick = SDL_JoystickOpen(i);
        if (joystick == NULL) {
            SDL_Log("Failed to open joystick %d: %s", i, SDL_GetError());
            continue;
        }
        SDL_Haptic* haptic = SDL_HapticOpen(i);
        if (haptic == NULL) {
            SDL_Log("Failed to open haptic %d: %s", i, SDL_GetError());
            SDL_JoystickClose(joystick);
            continue;
        }
        if (SDL_HapticRumbleInit(haptic) != 0) {
            SDL_Log("Failed to init rumble %d: %s", i, SDL_GetError());
            SDL_HapticClose(haptic);
            SDL_JoystickClose(joystick);
            continue;
        }
        joysticks.push_back(std::make_pair(joystick, haptic));
        SDL_Log("Opened joystick and haptic %d", i);
    }

    return 0;
}

void rumble_if_button(int button, const std::pair<SDL_Joystick*, SDL_Haptic*>& joystick, float power) {
    Uint8 state = SDL_JoystickGetButton(joystick.first, button);
    if (state == (Uint8) 1) {
        if (SDL_HapticRumblePlay(joystick.second, power, 250) != 0) {
            SDL_Log("Failed to rumble %s", SDL_GetError());
        } else {
            SDL_Log("Rumbled %.2f", power);
        }
    }
}

int main(int argc, const char* argv[]) {

    if (SDL_Init(SDL_INIT_JOYSTICK | SDL_INIT_HAPTIC) != 0) {
        SDL_Log("Failed to initialize: %s", SDL_GetError());
        return 1;
    }

    struct sigaction handler;

    handler.sa_handler = ctrlc_handler;
    sigemptyset(&handler.sa_mask);
    handler.sa_flags = 0;
    sigaction(SIGINT, &handler, NULL);

    if (init_joysticks() != 0) {
        return 1;
    }

    bool run = joysticks.size() > 0;
    while (run) {
        SDL_JoystickUpdate();
        for (std::pair<SDL_Joystick*, SDL_Haptic*> joystick : joysticks) {
            Uint8 state = SDL_JoystickGetButton(joystick.first, 0);
            
            if (state == (Uint8) 1) {
                SDL_Log("Quitting");
                run = false;
            }

            rumble_if_button(1, joystick, 1.0F);
            rumble_if_button(2, joystick, 0.25F);
            rumble_if_button(3, joystick, 0.5F);

            SDL_Delay(50);
        }
    }

    shutdown_joysticks();

    return 0;
}

Use the following for meson:

project('rumble', 'cpp')
sdldep = dependency('sdl2')
executable('rumble', 'rumble.cpp', dependencies : sdldep)